Merge "Add AudioRecordingConfiguration changed callback"

8 files changed, 477 insertions, 6 deletions

diff --git a/api/current.txt b/api/current.txt
index d881857b3c0f..f9b566087a8b 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -23379,12 +23379,13 @@ package android.media {
     method public android.media.AudioPresentation.Builder setProgramId(int);
   }
 
-  public class AudioRecord implements android.media.AudioRouting {
+  public class AudioRecord implements android.media.AudioRecordingMonitor android.media.AudioRouting {
     ctor public AudioRecord(int, int, int, int, int) throws java.lang.IllegalArgumentException;
     method public void addOnRoutingChangedListener(android.media.AudioRouting.OnRoutingChangedListener, android.os.Handler);
     method public deprecated void addOnRoutingChangedListener(android.media.AudioRecord.OnRoutingChangedListener, android.os.Handler);
     method protected void finalize();
     method public java.util.List<android.media.MicrophoneInfo> getActiveMicrophones() throws java.io.IOException;
+    method public android.media.AudioRecordingConfiguration getActiveRecordingConfiguration();
     method public int getAudioFormat();
     method public int getAudioSessionId();
     method public int getAudioSource();
@@ -23409,6 +23410,7 @@ package android.media {
     method public int read(float[], int, int, int);
     method public int read(java.nio.ByteBuffer, int);
     method public int read(java.nio.ByteBuffer, int, int);
+    method public void registerAudioRecordingCallback(java.util.concurrent.Executor, android.media.AudioManager.AudioRecordingCallback);
     method public void release();
     method public void removeOnRoutingChangedListener(android.media.AudioRouting.OnRoutingChangedListener);
     method public deprecated void removeOnRoutingChangedListener(android.media.AudioRecord.OnRoutingChangedListener);
@@ -23420,6 +23422,7 @@ package android.media {
     method public void startRecording() throws java.lang.IllegalStateException;
     method public void startRecording(android.media.MediaSyncEvent) throws java.lang.IllegalStateException;
     method public void stop() throws java.lang.IllegalStateException;
+    method public void unregisterAudioRecordingCallback(android.media.AudioManager.AudioRecordingCallback);
     field public static final int ERROR = -1; // 0xffffffff
     field public static final int ERROR_BAD_VALUE = -2; // 0xfffffffe
     field public static final int ERROR_DEAD_OBJECT = -6; // 0xfffffffa
@@ -23474,6 +23477,12 @@ package android.media {
     field public static final android.os.Parcelable.Creator<android.media.AudioRecordingConfiguration> CREATOR;
   }
 
+  public abstract interface AudioRecordingMonitor {
+    method public abstract android.media.AudioRecordingConfiguration getActiveRecordingConfiguration();
+    method public abstract void registerAudioRecordingCallback(java.util.concurrent.Executor, android.media.AudioManager.AudioRecordingCallback);
+    method public abstract void unregisterAudioRecordingCallback(android.media.AudioManager.AudioRecordingCallback);
+  }
+
   public abstract interface AudioRouting {
     method public abstract void addOnRoutingChangedListener(android.media.AudioRouting.OnRoutingChangedListener, android.os.Handler);
     method public abstract android.media.AudioDeviceInfo getPreferredDevice();
@@ -25475,11 +25484,12 @@ package android.media {
     field public static final int MEDIA_TRACK_TYPE_VIDEO = 1; // 0x1
   }
 
-  public class MediaRecorder implements android.media.AudioRouting {
+  public class MediaRecorder implements android.media.AudioRecordingMonitor android.media.AudioRouting {
     ctor public MediaRecorder();
     method public void addOnRoutingChangedListener(android.media.AudioRouting.OnRoutingChangedListener, android.os.Handler);
     method protected void finalize();
     method public java.util.List<android.media.MicrophoneInfo> getActiveMicrophones() throws java.io.IOException;
+    method public android.media.AudioRecordingConfiguration getActiveRecordingConfiguration();
     method public static final int getAudioSourceMax();
     method public int getMaxAmplitude() throws java.lang.IllegalStateException;
     method public android.os.PersistableBundle getMetrics();
@@ -25488,6 +25498,7 @@ package android.media {
     method public android.view.Surface getSurface();
     method public void pause() throws java.lang.IllegalStateException;
     method public void prepare() throws java.io.IOException, java.lang.IllegalStateException;
+    method public void registerAudioRecordingCallback(java.util.concurrent.Executor, android.media.AudioManager.AudioRecordingCallback);
     method public void release();
     method public void removeOnRoutingChangedListener(android.media.AudioRouting.OnRoutingChangedListener);
     method public void reset();
@@ -25523,6 +25534,7 @@ package android.media {
     method public void setVideoSource(int) throws java.lang.IllegalStateException;
     method public void start() throws java.lang.IllegalStateException;
     method public void stop() throws java.lang.IllegalStateException;
+    method public void unregisterAudioRecordingCallback(android.media.AudioManager.AudioRecordingCallback);
     field public static final int MEDIA_ERROR_SERVER_DIED = 100; // 0x64
     field public static final int MEDIA_RECORDER_ERROR_UNKNOWN = 1; // 0x1
     field public static final int MEDIA_RECORDER_INFO_MAX_DURATION_REACHED = 800; // 0x320
diff --git a/api/system-current.txt b/api/system-current.txt
index 565623c5e0d8..3aa7cc7a1bdb 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -2953,7 +2953,7 @@ package android.media {
     field public static final int PLAYER_TYPE_UNKNOWN = -1; // 0xffffffff
   }
 
-  public class AudioRecord implements android.media.AudioRouting {
+  public class AudioRecord implements android.media.AudioRecordingMonitor android.media.AudioRouting {
     ctor public AudioRecord(android.media.AudioAttributes, android.media.AudioFormat, int, int) throws java.lang.IllegalArgumentException;
   }
 
diff --git a/media/java/android/media/AudioRecord.java b/media/java/android/media/AudioRecord.java
index 4b2353c992f2..33f81f1db69c 100644
--- a/media/java/android/media/AudioRecord.java
+++ b/media/java/android/media/AudioRecord.java
@@ -16,8 +16,10 @@
 
 package android.media;
 
+import android.annotation.CallbackExecutor;
 import android.annotation.IntDef;
 import android.annotation.NonNull;
+import android.annotation.Nullable;
 import android.annotation.SystemApi;
 import android.annotation.UnsupportedAppUsage;
 import android.app.ActivityThread;
@@ -43,6 +45,7 @@ import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
+import java.util.concurrent.Executor;
 
 /**
  * The AudioRecord class manages the audio resources for Java applications
@@ -58,7 +61,7 @@ import java.util.List;
  * been read yet. Data should be read from the audio hardware in chunks of sizes inferior to
  * the total recording buffer size.
  */
-public class AudioRecord implements AudioRouting
+public class AudioRecord implements AudioRouting, AudioRecordingMonitor, AudioRecordingMonitorClient
 {
     //---------------------------------------------------------
     // Constants
@@ -1654,6 +1657,56 @@ public class AudioRecord implements AudioRouting
         return activeMicrophones;
     }
 
+
+    //--------------------------------------------------------------------------
+    // Implementation of AudioRecordingMonitor interface
+    //--------------------
+
+    AudioRecordingMonitorImpl mRecordingInfoImpl =
+            new AudioRecordingMonitorImpl((AudioRecordingMonitorClient) this);
+
+    /**
+     * Register a callback to be notified of audio capture changes via a
+     * {@link AudioManager.AudioRecordingCallback}. A callback is received when the capture path
+     * configuration changes (pre-processing, format, sampling rate...) or capture is
+     * silenced/unsilenced by the system.
+     * @param executor {@link Executor} to handle the callbacks.
+     * @param cb non-null callback to register
+     */
+    public void registerAudioRecordingCallback(@NonNull @CallbackExecutor Executor executor,
+            @NonNull AudioManager.AudioRecordingCallback cb) {
+        mRecordingInfoImpl.registerAudioRecordingCallback(executor, cb);
+    }
+
+    /**
+     * Unregister an audio recording callback previously registered with
+     * {@link #registerAudioRecordingCallback(Executor, AudioManager.AudioRecordingCallback)}.
+     * @param cb non-null callback to unregister
+     */
+    public void unregisterAudioRecordingCallback(@NonNull AudioManager.AudioRecordingCallback cb) {
+        mRecordingInfoImpl.unregisterAudioRecordingCallback(cb);
+    }
+
+    /**
+     * Returns the current active audio recording for this audio recorder.
+     * @return a valid {@link AudioRecordingConfiguration} if this recorder is active
+     * or null otherwise.
+     * @see AudioRecordingConfiguration
+     */
+    public @Nullable AudioRecordingConfiguration getActiveRecordingConfiguration() {
+        return mRecordingInfoImpl.getActiveRecordingConfiguration();
+    }
+
+    //---------------------------------------------------------
+    // Implementation of AudioRecordingMonitorClient interface
+    //--------------------
+    /**
+     * @hide
+     */
+    public int getPortId() {
+        return native_getPortId();
+    }
+
     //---------------------------------------------------------
     // Interface definitions
     //--------------------
diff --git a/media/java/android/media/AudioRecordingMonitor.java b/media/java/android/media/AudioRecordingMonitor.java
new file mode 100644
index 000000000000..e2605d074c86
--- /dev/null
+++ b/media/java/android/media/AudioRecordingMonitor.java
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.media;
+
+import android.annotation.CallbackExecutor;
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+
+import java.util.concurrent.Executor;
+
+/**
+ * AudioRecordingMonitor defines an interface implemented by {@link AudioRecord} and
+ * {@link MediaRecorder} allowing applications to install a callback and be notified of changes
+ * in the capture path while recoding is active.
+ */
+public interface AudioRecordingMonitor {
+    /**
+     * Register a callback to be notified of audio capture changes via a
+     * {@link AudioManager.AudioRecordingCallback}. A callback is received when the capture path
+     * configuration changes (pre-processing, format, sampling rate...) or capture is
+     * silenced/unsilenced by the system.
+     * @param executor {@link Executor} to handle the callbacks.
+     * @param cb non-null callback to register
+     */
+    void registerAudioRecordingCallback(@NonNull @CallbackExecutor Executor executor,
+            @NonNull AudioManager.AudioRecordingCallback cb);
+
+    /**
+     * Unregister an audio recording callback previously registered with
+     * {@link #registerAudioRecordingCallback(Executor, AudioManager.AudioRecordingCallback)}.
+     * @param cb non-null callback to unregister
+     */
+    void unregisterAudioRecordingCallback(@NonNull AudioManager.AudioRecordingCallback cb);
+
+    /**
+     * Returns the current active audio recording for this audio recorder.
+     * @return a valid {@link AudioRecordingConfiguration} if this recorder is active
+     * or null otherwise.
+     * @see AudioRecordingConfiguration
+     */
+    @Nullable AudioRecordingConfiguration getActiveRecordingConfiguration();
+}
diff --git a/media/java/android/media/AudioRecordingMonitorClient.java b/media/java/android/media/AudioRecordingMonitorClient.java
new file mode 100644
index 000000000000..7578d9b9a5fd
--- /dev/null
+++ b/media/java/android/media/AudioRecordingMonitorClient.java
@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.media;
+
+/**
+ * Interface implemented by classes using { @link AudioRecordingMonitor} interface.
+ * @hide
+ */
+public interface AudioRecordingMonitorClient {
+    /**
+     * @return the unique port ID allocated by audio framework to this recorder
+     */
+    int getPortId();
+}
diff --git a/media/java/android/media/AudioRecordingMonitorImpl.java b/media/java/android/media/AudioRecordingMonitorImpl.java
new file mode 100644
index 000000000000..c2cd4bc0b7eb
--- /dev/null
+++ b/media/java/android/media/AudioRecordingMonitorImpl.java
@@ -0,0 +1,250 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.media;
+
+import android.annotation.CallbackExecutor;
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.content.Context;
+import android.os.Binder;
+import android.os.Handler;
+import android.os.HandlerThread;
+import android.os.IBinder;
+import android.os.Looper;
+import android.os.Message;
+import android.os.RemoteException;
+import android.os.ServiceManager;
+import android.util.Log;
+
+import com.android.internal.annotations.GuardedBy;
+
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.concurrent.Executor;
+
+/**
+ * Implementation of AudioRecordingMonitor interface.
+ * @hide
+ */
+public class AudioRecordingMonitorImpl implements AudioRecordingMonitor {
+
+    private static final String TAG = "android.media.AudioRecordingMonitor";
+
+    private static IAudioService sService; //lazy initialization, use getService()
+
+    private final AudioRecordingMonitorClient mClient;
+
+    AudioRecordingMonitorImpl(@NonNull AudioRecordingMonitorClient client) {
+        mClient = client;
+    }
+
+    /**
+     * Register a callback to be notified of audio capture changes via a
+     * {@link AudioManager.AudioRecordingCallback}. A callback is received when the capture path
+     * configuration changes (pre-processing, format, sampling rate...) or capture is
+     * silenced/unsilenced by the system.
+     * @param executor {@link Executor} to handle the callbacks.
+     * @param cb non-null callback to register
+     */
+    public void registerAudioRecordingCallback(@NonNull @CallbackExecutor Executor executor,
+            @NonNull AudioManager.AudioRecordingCallback cb) {
+        if (cb == null) {
+            throw new IllegalArgumentException("Illegal null AudioRecordingCallback");
+        }
+        if (executor == null) {
+            throw new IllegalArgumentException("Illegal null Executor");
+        }
+        synchronized (mRecordCallbackLock) {
+            // check if eventCallback already in list
+            for (AudioRecordingCallbackInfo arci : mRecordCallbackList) {
+                if (arci.mCb == cb) {
+                    throw new IllegalArgumentException(
+                            "AudioRecordingCallback already registered");
+                }
+            }
+            beginRecordingCallbackHandling();
+            mRecordCallbackList.add(new AudioRecordingCallbackInfo(executor, cb));
+        }
+    }
+
+    /**
+     * Unregister an audio recording callback previously registered with
+     * {@link #registerAudioRecordingCallback(Executor, AudioManager.AudioRecordingCallback)}.
+     * @param cb non-null callback to unregister
+     */
+    public void unregisterAudioRecordingCallback(@NonNull AudioManager.AudioRecordingCallback cb) {
+        if (cb == null) {
+            throw new IllegalArgumentException("Illegal null AudioRecordingCallback argument");
+        }
+
+        synchronized (mRecordCallbackLock) {
+            for (AudioRecordingCallbackInfo arci : mRecordCallbackList) {
+                if (arci.mCb == cb) {
+                    // ok to remove while iterating over list as we exit iteration
+                    mRecordCallbackList.remove(arci);
+                    if (mRecordCallbackList.size() == 0) {
+                        endRecordingCallbackHandling();
+                    }
+                    return;
+                }
+            }
+            throw new IllegalArgumentException("AudioRecordingCallback was not registered");
+        }
+    }
+
+    /**
+     * Returns the current active audio recording for this audio recorder.
+     * @return a valid {@link AudioRecordingConfiguration} if this recorder is active
+     * or null otherwise.
+     * @see AudioRecordingConfiguration
+     */
+    public @Nullable AudioRecordingConfiguration getActiveRecordingConfiguration() {
+        final IAudioService service = getService();
+        try {
+            List<AudioRecordingConfiguration> configs = service.getActiveRecordingConfigurations();
+            return getMyConfig(configs);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+
+    private static class AudioRecordingCallbackInfo {
+        final AudioManager.AudioRecordingCallback mCb;
+        final Executor mExecutor;
+        AudioRecordingCallbackInfo(Executor e, AudioManager.AudioRecordingCallback cb) {
+            mExecutor = e;
+            mCb = cb;
+        }
+    }
+
+    private static final int MSG_RECORDING_CONFIG_CHANGE = 1;
+
+    private final Object mRecordCallbackLock = new Object();
+    @GuardedBy("mRecordCallbackLock")
+    @NonNull private LinkedList<AudioRecordingCallbackInfo> mRecordCallbackList =
+            new LinkedList<AudioRecordingCallbackInfo>();
+    @GuardedBy("mRecordCallbackLock")
+    private @Nullable HandlerThread mRecordingCallbackHandlerThread;
+    @GuardedBy("mRecordCallbackLock")
+    private @Nullable volatile Handler mRecordingCallbackHandler;
+
+    @GuardedBy("mRecordCallbackLock")
+    private final IRecordingConfigDispatcher mRecordingCallback =
+            new IRecordingConfigDispatcher.Stub() {
+        @Override
+        public void dispatchRecordingConfigChange(List<AudioRecordingConfiguration> configs) {
+            AudioRecordingConfiguration config = getMyConfig(configs);
+            if (config != null) {
+                synchronized (mRecordCallbackLock) {
+                    if (mRecordingCallbackHandler != null) {
+                        final Message m = mRecordingCallbackHandler.obtainMessage(
+                                              MSG_RECORDING_CONFIG_CHANGE/*what*/, config /*obj*/);
+                        mRecordingCallbackHandler.sendMessage(m);
+                    }
+                }
+            }
+        }
+    };
+
+    @GuardedBy("mRecordCallbackLock")
+    private void beginRecordingCallbackHandling() {
+        if (mRecordingCallbackHandlerThread == null) {
+            mRecordingCallbackHandlerThread = new HandlerThread(TAG + ".RecordingCallback");
+            mRecordingCallbackHandlerThread.start();
+            final Looper looper = mRecordingCallbackHandlerThread.getLooper();
+            if (looper != null) {
+                mRecordingCallbackHandler = new Handler(looper) {
+                    @Override
+                    public void handleMessage(Message msg) {
+                        switch (msg.what) {
+                            case MSG_RECORDING_CONFIG_CHANGE: {
+                                if (msg.obj == null) {
+                                    return;
+                                }
+                                ArrayList<AudioRecordingConfiguration> configs =
+                                        new ArrayList<AudioRecordingConfiguration>();
+                                configs.add((AudioRecordingConfiguration) msg.obj);
+
+                                final LinkedList<AudioRecordingCallbackInfo> cbInfoList;
+                                synchronized (mRecordCallbackLock) {
+                                    if (mRecordCallbackList.size() == 0) {
+                                        return;
+                                    }
+                                    cbInfoList = new LinkedList<AudioRecordingCallbackInfo>(
+                                        mRecordCallbackList);
+                                }
+
+                                final long identity = Binder.clearCallingIdentity();
+                                try {
+                                    for (AudioRecordingCallbackInfo cbi : cbInfoList) {
+                                        cbi.mExecutor.execute(() ->
+                                                cbi.mCb.onRecordingConfigChanged(configs));
+                                    }
+                                } finally {
+                                    Binder.restoreCallingIdentity(identity);
+                                }
+                            } break;
+                            default:
+                                Log.e(TAG, "Unknown event " + msg.what);
+                                break;
+                        }
+                    }
+                };
+                final IAudioService service = getService();
+                try {
+                    service.registerRecordingCallback(mRecordingCallback);
+                } catch (RemoteException e) {
+                    throw e.rethrowFromSystemServer();
+                }
+            }
+        }
+    }
+
+    @GuardedBy("mRecordCallbackLock")
+    private void endRecordingCallbackHandling() {
+        if (mRecordingCallbackHandlerThread != null) {
+            final IAudioService service = getService();
+            try {
+                service.unregisterRecordingCallback(mRecordingCallback);
+            } catch (RemoteException e) {
+                throw e.rethrowFromSystemServer();
+            }
+            mRecordingCallbackHandlerThread.quit();
+            mRecordingCallbackHandlerThread = null;
+        }
+    }
+
+    AudioRecordingConfiguration getMyConfig(List<AudioRecordingConfiguration> configs) {
+        int portId = mClient.getPortId();
+        for (AudioRecordingConfiguration config : configs) {
+            if (config.getClientPortId() == portId) {
+                return config;
+            }
+        }
+        return null;
+    }
+
+    private static IAudioService getService() {
+        if (sService != null) {
+            return sService;
+        }
+        IBinder b = ServiceManager.getService(Context.AUDIO_SERVICE);
+        sService = IAudioService.Stub.asInterface(b);
+        return sService;
+    }
+}
diff --git a/media/java/android/media/MediaRecorder.java b/media/java/android/media/MediaRecorder.java
index 8ced021b1025..1cdc29102758 100644
--- a/media/java/android/media/MediaRecorder.java
+++ b/media/java/android/media/MediaRecorder.java
@@ -16,7 +16,9 @@
 
 package android.media;
 
+import android.annotation.CallbackExecutor;
 import android.annotation.NonNull;
+import android.annotation.Nullable;
 import android.annotation.RequiresPermission;
 import android.annotation.SystemApi;
 import android.annotation.UnsupportedAppUsage;
@@ -40,6 +42,8 @@ import java.io.RandomAccessFile;
 import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.concurrent.Executor;
+
 
 /**
  * Used to record audio and video. The recording control is based on a
@@ -83,7 +87,9 @@ import java.util.List;
  * <a href="{@docRoot}guide/topics/media/audio-capture.html">Audio Capture</a> developer guide.</p>
  * </div>
  */
-public class MediaRecorder implements AudioRouting
+public class MediaRecorder implements AudioRouting,
+                                      AudioRecordingMonitor,
+                                      AudioRecordingMonitorClient
 {
     static {
         System.loadLibrary("media_jni");
@@ -304,7 +310,7 @@ public class MediaRecorder implements AudioRouting
 
         /**
          * Audio source for preemptible, low-priority software hotword detection
-         * It presents the same gain and pre processing tuning as {@link #VOICE_RECOGNITION}.
+         * It presents the same gain and pre-processing tuning as {@link #VOICE_RECOGNITION}.
          * <p>
          * An application should use this audio source when it wishes to do
          * always-on software hotword detection, while gracefully giving in to any other application
@@ -1471,6 +1477,57 @@ public class MediaRecorder implements AudioRouting
     private native final int native_getActiveMicrophones(
             ArrayList<MicrophoneInfo> activeMicrophones);
 
+    //--------------------------------------------------------------------------
+    // Implementation of AudioRecordingMonitor interface
+    //--------------------
+
+    AudioRecordingMonitorImpl mRecordingInfoImpl =
+            new AudioRecordingMonitorImpl((AudioRecordingMonitorClient) this);
+
+    /**
+     * Register a callback to be notified of audio capture changes via a
+     * {@link AudioManager.AudioRecordingCallback}. A callback is received when the capture path
+     * configuration changes (pre-processing, format, sampling rate...) or capture is
+     * silenced/unsilenced by the system.
+     * @param executor {@link Executor} to handle the callbacks.
+     * @param cb non-null callback to register
+     */
+    public void registerAudioRecordingCallback(@NonNull @CallbackExecutor Executor executor,
+            @NonNull AudioManager.AudioRecordingCallback cb) {
+        mRecordingInfoImpl.registerAudioRecordingCallback(executor, cb);
+    }
+
+    /**
+     * Unregister an audio recording callback previously registered with
+     * {@link #registerAudioRecordingCallback(Executor, AudioManager.AudioRecordingCallback)}.
+     * @param cb non-null callback to unregister
+     */
+    public void unregisterAudioRecordingCallback(@NonNull AudioManager.AudioRecordingCallback cb) {
+        mRecordingInfoImpl.unregisterAudioRecordingCallback(cb);
+    }
+
+    /**
+     * Returns the current active audio recording for this audio recorder.
+     * @return a valid {@link AudioRecordingConfiguration} if this recorder is active
+     * or null otherwise.
+     * @see AudioRecordingConfiguration
+     */
+    public @Nullable AudioRecordingConfiguration getActiveRecordingConfiguration() {
+        return mRecordingInfoImpl.getActiveRecordingConfiguration();
+    }
+
+    //---------------------------------------------------------
+    // Implementation of AudioRecordingMonitorClient interface
+    //--------------------
+    /**
+     * @hide
+     */
+    public int getPortId() {
+        return native_getPortId();
+    }
+
+    private native int native_getPortId();
+
     /**
      * Called from native code when an interesting event happens.  This method
      * just uses the EventHandler system to post the event back to the main app thread.
diff --git a/media/jni/android_media_MediaRecorder.cpp b/media/jni/android_media_MediaRecorder.cpp
index b3a8b21147c1..ca30f32ea438 100644
--- a/media/jni/android_media_MediaRecorder.cpp
+++ b/media/jni/android_media_MediaRecorder.cpp
@@ -763,6 +763,20 @@ android_media_MediaRecord_getActiveMicrophones(JNIEnv *env,
     }
     return jStatus;
 }
+
+static jint android_media_MediaRecord_getPortId(JNIEnv *env,  jobject thiz) {
+    sp<MediaRecorder> mr = getMediaRecorder(env, thiz);
+    if (mr == NULL) {
+        jniThrowException(env, "java/lang/IllegalStateException", NULL);
+        return (jint)AUDIO_PORT_HANDLE_NONE;
+    }
+
+    audio_port_handle_t portId;
+    process_media_recorder_call(env, mr->getPortId(&portId),
+                                "java/lang/RuntimeException", "getPortId failed.");
+    return (jint)portId;
+}
+
 // ----------------------------------------------------------------------------
 
 static const JNINativeMethod gMethods[] = {
@@ -801,6 +815,7 @@ static const JNINativeMethod gMethods[] = {
     {"native_enableDeviceCallback", "(Z)V",                     (void *)android_media_MediaRecorder_enableDeviceCallback},
 
     {"native_getActiveMicrophones", "(Ljava/util/ArrayList;)I", (void *)android_media_MediaRecord_getActiveMicrophones},
+    {"native_getPortId", "()I", (void *)android_media_MediaRecord_getPortId},
 };
 
 // This function only registers the native methods, and is called from